The reliability of a typical capacitor is verified over parameter ranges which traditionally are designed to test the capacitor at extreme operating values. For example, a capacitor may be temperature-cycled from about zero degrees Celsius to over 250 degrees Celsius while monitoring its performance to determine if it is operating within acceptable tolerances. The voltage applied to the capacitor can also be cycled either independently or at the same time as the temperature testing to identify nonstandard or defective devices. Such testing is useful and will accurately identify acceptable capacitors over their extreme parameter ranges.
Such a testing paradigm assumes that the capacitor's physical properties do not substantially change over the course of testing. This was a good assumption for most traditional capacitor designs; however, more recent types of ceramic dielectric materials and electrode combinations demonstrate substantially different electrical properties at temperatures and/or voltages which are much different than the extreme values over which capacitors have been traditionally tested. Consequently, there is a need in the art for new capacitor testing methods and apparatus which accounts for changing physical properties over the temperature and voltage ranges of interest. Such testing methods and apparatus should reliably identify devices which cannot meet predetermined tolerances or which fail upon testing.